They should be free, you might need to download a weapons pack from the workshop and other maps should be available their or when you load a map on a server.
You might just find your missing some textures though and I’m not sure if their available on the workshop or not. You’ll just end up with a ugly looking maps if you don’t have them, but it should still be playable.
My favourite game modes are prop hunt, which is a hide and seek, but your glass bottles or tin cans and the other team trys to kill you.
There are other game types like role-play, but I’ve never played them.
Or TTT, which your either a innocent, detective or traitor. When your a T you have to kill off the others. as i innocent you have to find the T’s with the help of the D who has a DNA scanner so can locate the person who killed the I.
It’s fun, but some admins are a little retentive, jus don’t loose your karma or you’ll get banned from a server, so you need proof before killing someone you suspect is a T, if their a I or D you’d loose karma. The same if you are a T and kill another T.